OT Sail downwind faster than the wind!

On Aug 17, 5:07 am, "amdx" wrote:

 One question, is the tacking of the prop necessary or could
a flat blade prop work? Some videos seem to think that is
the key, but your analysis would refute this.

I'm not sure if you're referring to a prop with no twist or a prop
with no pitch.  The prop has to have at minimum an effectively
positive pitch.

On Tue, 17 Aug 2010 00:08:22 -0700 (PDT), Rick Cavallaro

rick.sp...@gmail.com> wrote:
On Aug 16, 9:52 pm, John Larkin wrote:

But mph-lbs?

Good call - if you can't find any actual errors in the analysis, bitch
about the units.

Is this trick going to be your life's work?

John

One question, is the tacking of the prop necessary or could
a flat blade prop work? Some videos seem to think that is
the key, but your analysis would refute this.

On Tue, 17 Aug 2010 07:07:04 -0500, "amdx" <amdx_at_knology.net> wrote:


"Rick Cavallaro" <rick.spork_at_gmail.com> wrote in message
news:88a33807-fec7-4af8-b81e-f0bc1d2ba1e3_at_i18g2000pro.googlegroups.com...
On Aug 16, 12:19 pm, "amdx" wrote:

Can you explain to me how this little vehicle goes uphill
faster than the treadmill speed. Please!

Certainly...

Consider a cart with a generator hooked to the rear axle. We'll
attach the propeller (it IS a propeller - not a turbine) to an
electric motor.

For the sake of argument I'm going to assume the following
efficiencies:

generator: 85%
electric motor: 85%
propeller: 85%

And just for now...
rolling resistance: 0 lbs
aerodynamic drag: 0 lbs
(we'll come back to these).


Now let's tow this cart up to 20 mph in a 15 mph tail-wind and let it
loose. That means it will feel a relative head-wind of 5 mph over the
cart. Now I'll adust my generator output until it produces 20 lbs of
drag at the wheels. This means I'm putting power in at a rate of 20
mph x 20 lbs (400 mph-lbs). But I only get 340 mph-lbs out of the
generator due to its limited efficiency. I deliver that power to the
electric motor. But I only get 289 mph-lbs at the motor's shaft due
to the motor's innefficiency. So I'm putting 289 mph-lbs into the
prop - but it's only doing about 245 mph-lbs work on the air due to
it's innefficiency.

So now lets see how much thrust I'm getting from my prop...

245 mph-lbs / 5 mph (the speed I'm moving through the air) gives 49
lbs.

So we're producing 49 lbs of thrust and only 20 lbs of drag. But we
haven't yet accounted for the rolling resistance and aero drag. If we
can get both of those numbers to come in at a total of less than 29
lbs (which should be a piece of cake) we'll be going 5 mph faster than
the wind and still accelerating. But why?

Simple. The car acts as a force multiplier (i.e. lever) between two
media (the ground and the air). Just like any lever, I can get more
force out of one end if I put more distance in the other. Force x
distance = work, so those will nominally be the same on both sides.
But my car is going over the ground at 20 mph while it's only going
through the air at 5 mph. This means the ground side of my lever
moves 20 miles in one hour while the air end of my lever moves only 5
miles in that same hour. With no losses I can get four times the
thrust as the drag I produce.

Thanks Rick,
I was hoping Jim would analyze it and start thinking hmm...
maybe this thing isn't intuative and why is, that car going
faster than the 0 mph wind.
I find it interesting that there are so many nonbelievers with
so many tests showing it works.
One question, is the tacking of the prop necessary or could
a flat blade prop work? Some videos seem to think that is
the key, but your analysis would refute this.
MikeK


I'm NOT a non-believer. Everything has an explanation that fits
_both_ observation _and_ science.

MikeK, You seem to have trouble understanding what TANSTAAFL means
?

On Tue, 17 Aug 2010 00:08:22 -0700 (PDT), Rick Cavallaro
rick.spork_at_gmail.com> wrote:

On Aug 16, 9:52 pm, John Larkin wrote:

But mph-lbs?

Good call - if you can't find any actual errors in the analysis, bitch
about the units.

Larkin is incapable of working with equivalent units. If mommy didn't
give him a formula he's totally lost

some video suggested the vehicle can go DDWFTTW be cause the prop
is tacking to the wind.

On Mon, 16 Aug 2010 12:51:34 -0500, "amdx" <amdx_at_knology.net> wrote:


Subject: GIRLYBOYS cat fighting again!!


I've returned to normalcy by simply plonking Larkin.

No agitation. No urge to lose my cool. No need to convince (and try
to educate) idiots that the fundamental rule of Life, Physics and
Engineering is "TANSTAAFL" :-)

Now I can ask and answer engineering questions without having to
contend with distracting bloviation.

Those who choose to believe in Larkin's (and his camp followers')
bloviation... well, that's their loss.

...Jim Thompson

On Tue, 17 Aug 2010 07:32:38 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon_at_On-My-Web-Site.com> wrote:

On Tue, 17 Aug 2010 00:08:22 -0700 (PDT), Rick Cavallaro
rick.spork_at_gmail.com> wrote:

On Aug 16, 9:52 pm, John Larkin wrote:

But mph-lbs?

Good call - if you can't find any actual errors in the analysis, bitch
about the units.

Larkin is incapable of working with equivalent units. If mommy didn't
give him a formula he's totally lost :-)

---
Shunning someone doesn't mean talking about them behind their back, it
means considering them not to exist, so there's nothing to talk about.

But, I guess you won't read this since it doesn't have a schematic
attached. :-(

---
JF

Jim Thompson wrote:
On Mon, 16 Aug 2010 12:51:34 -0500, "amdx" <amdx_at_knology.net> wrote:


Subject: GIRLYBOYS cat fighting again!!


I've returned to normalcy by simply plonking Larkin.

No agitation. No urge to lose my cool. No need to convince (and try
to educate) idiots that the fundamental rule of Life, Physics and
Engineering is "TANSTAAFL" :-)

Now I can ask and answer engineering questions without having to
contend with distracting bloviation.

Those who choose to believe in Larkin's (and his camp followers')
bloviation... well, that's their loss.

...Jim Thompson


Keep that up and you'll have no one to talk with..

On Aug 17, 6:32 am, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Tue, 17 Aug 2010 00:08:22 -0700 (PDT), Rick Cavallaro

rick.sp...@gmail.com> wrote:
On Aug 16, 9:52 pm, John Larkin wrote:

But mph-lbs?

Good call - if you can't find any actual errors in the analysis, bitch
about the units.

Is this trick going to be your life's work?

John

He sure busted you at one of the things you do best.

Bwuahahahahaha!

On Aug 14, 3:53 am, Jasen Betts <ja...@xnet.co.nz> wrote:
On 2010-08-08, Nunya <jack_sheph...@cox.net> wrote:

  Sounds like we should add a big clock spring emergency
spin mechanism under the rotor and above the engine that
is never engaged, but gets engaged in the last hundred feet
of an emergency descent so that just a slight bit more last
second lift can be achieved.  It would be worth the extra 100Lbs.

if you activated that the helicopter would tend to spin out of control
at the worst possible moment due to autotorque, which is not present
(or even slightly negative) with the blades autorotating, but would
become suddenly positive (and varying) with the spring motor engaged.

IMO external airbags would be cheaper, lighter, and more effective.

--
¡spu?? ou '?? ?oo?

--- news://freenews.netfront.net/ - complaints: n...@netfront.net ---

One would, of course, use the spring motor to turn the tail rotor as
well,
or a small rocket could be fired to act against it so that all the
spring
motor energy could be placed into the rotor.

Hell. Put four rockets on the skid frame and fire those right at
the end.
They are lighter than any spring motor would be.

Back to electronics. Will there ever be an electric helicopter in a
man sized form factor?

On Sat, 14 Aug 2010 07:36:17 -0700 (PDT), Nunya
jack_shephard_at_cox.net> wrote:

On Aug 14, 3:53 am, Jasen Betts <ja...@xnet.co.nz> wrote:
On 2010-08-08, Nunya <jack_sheph...@cox.net> wrote:

Sounds like we should add a big clock spring emergency
spin mechanism under the rotor and above the engine that
is never engaged, but gets engaged in the last hundred feet
of an emergency descent so that just a slight bit more last
second lift can be achieved. It would be worth the extra 100Lbs.

if you activated that the helicopter would tend to spin out of control
at the worst possible moment due to autotorque, which is not present
(or even slightly negative) with the blades autorotating, but would
become suddenly positive (and varying) with the spring motor engaged.

IMO external airbags would be cheaper, lighter, and more effective.

--
¡spu?? ou '?? ?oo?

--- news://freenews.netfront.net/ - complaints: n...@netfront.net ---

One would, of course, use the spring motor to turn the tail rotor as
well,
or a small rocket could be fired to act against it so that all the
spring
motor energy could be placed into the rotor.

Hell. Put four rockets on the skid frame and fire those right at
the end.
They are lighter than any spring motor would be.

Back to electronics. Will there ever be an electric helicopter in a
man sized form factor?

That shouldn't be hard, for some minutes at least. The Tesla
accelerates like mad. Batteries and motors can make a lot of power for
a little while.

John

"John Larkin" <jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote in message
news:jphm6657ovuj8ln3n8geq7s2hppm1c530r_at_4ax.com...
On Sat, 14 Aug 2010 07:36:17 -0700 (PDT), Nunya
jack_shephard_at_cox.net> wrote:

On Aug 14, 3:53 am, Jasen Betts <ja...@xnet.co.nz> wrote:
On 2010-08-08, Nunya <jack_sheph...@cox.net> wrote:

Sounds like we should add a big clock spring emergency
spin mechanism under the rotor and above the engine that
is never engaged, but gets engaged in the last hundred feet
of an emergency descent so that just a slight bit more last
second lift can be achieved. It would be worth the extra 100Lbs.

if you activated that the helicopter would tend to spin out of control
at the worst possible moment due to autotorque, which is not present
(or even slightly negative) with the blades autorotating, but would
become suddenly positive (and varying) with the spring motor engaged.

IMO external airbags would be cheaper, lighter, and more effective.

--
¡spu?? ou '?? ?oo?

--- news://freenews.netfront.net/ - complaints: n...@netfront.net ---

One would, of course, use the spring motor to turn the tail rotor as
well,
or a small rocket could be fired to act against it so that all the
spring
motor energy could be placed into the rotor.

Hell. Put four rockets on the skid frame and fire those right at
the end.
They are lighter than any spring motor would be.

Back to electronics. Will there ever be an electric helicopter in a
man sized form factor?

That shouldn't be hard, for some minutes at least. The Tesla
accelerates like mad. Batteries and motors can make a lot of power for
a little while.

John

A VERY first order rule of thumb is you lift 10 pounds for each horsepower.

tm

On Aug 17, 7:35 pm, John Larkin whined:

What I do best is design electronics. He doesn't. You don't either.

He apparently knows only one trick, plays it everywhere, and it isn't
even his trick.

I thought we already established that I have a life and a pile of
accomplishments, and you're a jealous little prick. Do we have to go
over this again with smaller words?